Case 7 - “Walking on Glass”
A runner in her late 20s had been dealing with some nagging pain on the bottom of her foot for several weeks. The pain was never bad enough to go to the doctor. That is, until the day she pushed off her right foot while running and felt a “pop” and then a sensation like a shard of glass piercing her foot just in front of her heel. The foot and ankle surgeon listened to her history and noted the findings on physical exam. An MRI was ordered to confirm the diagnosis.
The first 2 MR images from our patient focus on the soft tissues of the bottom of the foot below the calcaneus (heel bone). The left image is a sagittal (from the side) projection. The linear, dark structure along the bottom of the foot is the plantar fascia [pronounced “fash-ee-uh”]. Normally, the plantar fascia is thin and smooth. Our patient, however, has a thickened plantar fascia with a focal partial disruption representing a partial tear (yellow arrow). This tear can also be seen in a coronal (from the front) image. Note the surrounding bright signal surrounding the fascia representing edema (excess fluid) and inflammation. Fortunately, the fascia has not completely torn and separated.
The second 2 MR images from another patient depict the normal appearance of the plantar fascia. Note the smooth, thin, intact appearance (yellow arrows) with no surrounding fluid or inflammation.
DIAGNOSIS: Plantar fascia tear (partial)
Tears of the plantar fascia are much less common than the dreaded, yet pervasive, plantar fasciitis. Whereas plantar fasciitis usually presents as the insidious onset of heel/foot pain, plantar fascia ruptures -- either partial or complete -- usually occur as an instantaneous event. The patient usually feels a “pop” and sudden pain with the inability to push off the affected foot. Plantar fasciosis (degeneration) or plantar fasciitis (inflammation) can precede and predispose to a tear. Treatment of a plantar fascia tear is almost always conservative. There is not much to do besides immobilize the foot, avoid weight-bearing, and wait for the fascia to scar down and heal itself. As with most conditions, prevention is easier (and much less painful) than the cure. Specific stretches for the plantar fascia and the related Achilles tendon and calf muscles can help avoid the troublesome path of plantar fascia difficulties.
Plantar fascia rupture: https://www.youtube.com/watch?v=eZF0XxUkJIM
Runner’s World article: The Best Recovery for Partial Plantar Tear
Dean Thornton, MD
Dean is a Musculoskeletal Radiologist with Radiology Associates of Birmingham and a Clinical Associate Professor of Radiology at UAB. He works with many local orthopedists and sports medicine physicians. He also likes to run.
Inside the Runner uses medical imaging to offer readers a chance to see what is going on inside their bodies when something breaks down. From fractures to tendonitis to muscle injuries, this series explores the imaging studies used to help doctors and other medical professionals treat running injuries.